George H.W. Bush's service, dog rests near his casket

Former President George H.W. Bush's service dog Sully, lying next to Bush's casket Dec. 2, 2018. The image was posted by Bush's spokesperson Jim McGrath on Twitter with the caption "Mission complete." (Photo: Evan Sisley, Office of George H. W. Bush)

As former President George H.W. Bush is being laid to rest, his service dog Sully is among those mourning the 94-year-old's death.

Sunday night, family spokesman Jim McGrath shared a photo of the yellow Labrador retriever sleeping next to Bush's casket. He wrote, "Mission complete."

Sully was appointed to the 41st president in June. At the time, Bush welcomed Sully, from nonprofit America's VetDogs, as a "member of the family" who was "beautifully trained."Since then, the dog accompanied Bush nearly everywhere, even the voting booth during the November midterm election.Sully will go on to work alongside other service dogs helping wounded soldiers and active duty personnel at the Walter Reed National Military Medical Center's Facility Dog Program, according to America's VetDogs.

Bush's family announced his death Friday. Monday, his remains were flown from Ellington Field in Houston to the Joint Base Andrews military facility in Maryland. The public may pay respects at the U.S. Capitol Rotunda in Washington from Monday to Wednesday.A look back at the life and legacy of former U.S. President George H.W. Bush who died on November 30th. USA TODAY

A state funeral will be held at the Washington National Cathedral, beginning at 11 a.m. Wednesday. It will be the first presidential funeral since Gerald Ford died in 2006.